32
Installation & Service Manual
4
System piping
2. Sustained high water velocity and low temperature
rise may result in pitting or erosion of the copper
tubes in the heat exchanger. This is a non-warrantable
failure. Temperature rise must be properly adjusted
to achieve the specified flow rate.
TABLE 4A
WATER HEATER
TEMPERATURE RISE
Btu/hr Input
Temperature Rise
150,000
4.6
199,999
6.2
250,000
7.7
300,000
9.3
The required temperature rise and the standard pump sizing are based on the heating of potable water with a hardness of 5
to 25 grains per gallon and a total dissolved solids not exceeding 350 PPM. Consult the manufacturer when heating potable
water exceeding these specifications. Heating of high hardness and/or high total dissolved solids water will require a larger
circulating pump, an optional cupro-nickel heat exchanger and a revised temperature rise specification based on the water
chemistry of the water to be heated. Water with a hardness of less than 5 grains per gallon will usually have a low pH which
can be aggressive and corrosive causing non-warrantable damage to the heater, pump and associated piping. Corrosion due to
water chemistry generally shows up first in the hot water system because heated water increases the rate of corrosive chemical
reactions.
Water chemistry
COLD WATER SUPPLY
MIXING
VALVE
THERMOMETER
BUILDING HOT
WATER SUPPLY
VERTICAL TANK INSTALLATION
LOCK-TEMP
STORAGE TANK
DRAIN
RELIEF VALVE
DOMESTIC WATER HEATER
SUPPLY BOILER
EXPANSION TANK IF REQUIRED
BUILDING
RETURN
Figure 4-3 Typical Water Heater Piping with Storage Tank
TABLE 4B
COMMON WATER MANIFOLD SIZE
FOR MULTIPLE WATER HEATER
INSTALLATIONS
Pipe sizing chart provides minimum pipe size for common
manifold piping to ensure adequate fl ow.
150,000 thru 300,000 Btu/hr Models
No. of Appliances
Common Manifold Size Min.)
1
2"
2
3"
3
3-1/2"
4
4"
5
5"
6
5"
Содержание Efficiency-Pac EW 150 -- 300
Страница 47: ...47 Notes ...
